Monday, May 14, 2012

Shooting from the hip: Another unregulated medical devices horror story

Gigamole had posted earlier about the possibility that a recent heart valve replacement surgery may not have been approved. Now for those who still insist on the "I-see-nothing" approach towards the issue of medical device regulation, here is a story to think about before you go to bed. Especially if you were one of those who had received a metal-on-metal hip replacement.

There is a kind of total hip prosthesis manuctured by a company called DePuy Orthopedics, a subsidiary of Johnson & Johnson. These hip replacements called the ASR Resurfacing System and the ASR XL Acetabular System, have metal cups as well as metal heads fitting into the cups. That's why they are referred to as metal-on-metal prostheses.

The prostheses first appeared at about 2003 and 2005 respectively, and were allowed into the US market without the need to do any clinical trials, through an FDA regulatory loop-hole called the 510(k) clearance. All seemed well and rosy until 2007 when Australia, one of the first to have a National Joint Replacement Registry detected that the prostheses had a relatively high rate of failure and surgical revision. Although the company knew about this, it continued to market the prostheses world-wide while phasing it out in the US. In 2010, the UK found similar failure rates and also issued 3 safety alerts. It wasn't just the hip prostheses failing. The metal surfaces grating on each other tended to flake of and expose patients to high levels of chromium and cobalt; some as much as 600 times higher than physiological levels.

In August 2010, the company finally issued a global recall.

In Singapore, these prostheses had been available since 2006. These entered the market and have been in use in patients for 4 years without any kind of regulatory approval. Because we do not have a joint replacement registry like Australia and do not track the post-surgical performance of these prostheses, we have been completely blinded when it came to device failures, and potential toxicities. Without a registry it has been almost impossible to enure that all patients implanted with these artificial joints can come forward to have their replacements replaced. We do not even check on whether these patients had or continue to have cobalt or chromium toxicity.

So patients in Singapore have a very serious problem. How many of our patients even know if they have had a DePuy hip replacement done? (Patients should ask their surgeon and call DePuy) Of these, how many have come forward and have been appropriately advised to get the corrective surgery done, at the cost of the company? Does the HSA know the extent of the problem? How are they looking after our patient's well being? Is anyone tracking cobalt and chromium levels in our patients?

The ASR problem hasn't quite gone away yet despite the global recall in 2010. The manufacturers have set aside billions of dollares to deal with potential lawsuits. Do our patients know they can sue the company?

Recently the BBC and the BMJ jointly reported on this regulatory failure. The manufacturer's apparently continued to market the device despite being aware of the problems.

The Lancet also carried a recent report, after analyzing the Joint Registry data from England and Wales, about how bad these metal-on-metal implants were.

Meanwhile, in Singapore, we don't even have a compulsory registry to know what is going on. The industry, media (and sadly the medical professionals as well) continue to whip up the hysteria suggesting that we should all leave well enough alone and not regulate medical devices at all. Gigamole is all for the HSA taking a stronger proactive position in protecting the interests of our patient-consumer. Methinks they have looked the other way long enough.